Element position detector system

ABSTRACT

An apparatus and detector system for sensing whether moving element of a series of elements are in a selected position which apparatus comprises sensor means mounted adjacent the path of travel of the series of elements, the sensor means being capable of projecting and receiving light, means for converting received, reflected light into a voltage pulse and means, including selected gating, for comparing the voltage pulse with other command or related derived signals.

ESQ- 961123 Unite Staes 1 WW,

Sweeney et al.

SUBSTITUTE FOR MISSING XR ELEMENT POSITION DETECTOR SYSTEM 3,529,4459/1970 Brose 66/i57 3,577,750 5/1971 V l 66/157 [75] lnvemm JamesSweeney Laguna Beach; 3,646,542 2/1972' Artistr 66/157 George A. Dyer,San Juan Capistrano; Ronald Johnson FOREIGN PATENTS OR APPLICATTONSAnaheim, all Of Calif. I 1,583,356 10/1969 France 66/154 A [73]Assignee: Rockwell International Corporation, OTHER PUBLICATIONSPittsburgh Rottmann, IBM Technical Disclosure Bulletin, Vol. 9, [22]Filed: Apr. 30, 1971 N0. 5, Oct. 1966, pp. 540 & 541

[21] Appl' l39l04 Primary ExaminerWm. Carter Reynolds Anorrieylohn R.Bronaugh, Floyd S. Levison, E. [52] U.S. Cl. 645/50 R, 66/157, 250/222R, Dennis OConnor and Richard A. Speer 250/227, 340/213 Q, 340/267 R,340/282 [5i] Int. Cl. D04b 15/78, D04b 35/18 [57] ABSTRACT 52 Field ofSearch 66/50 R, 501;, 25, An apparatus and detector system for Sensingwhether 66/50 1 157; 250/222 RI moving element of a series of elementsare in a se- 2273 340/213 267 282 lected position which apparatuscomprises sensor means mounted adjacent the path of travel of the se-[561 Relemnces cued ries of elements, the sensor means being capable ofUNITED STATES PATENTS projecting and receiving light, means forconverting 2,493,543 1/1950 Merchant 340/258 B x received, reflectedlight into a voltage Pulse and 3,646,542 2/1972 Anthony 66/157 X means,including selected gating, for comparing the "3,313,128 4/1967 Schmidtet a1 66/50 A voltage pulse with other command or related derived3,365,699 H1968 Foster 250/227 X signal 3,449,928 6/1969 Schmidt et al.1 66/50 R 3,449,931 6/1969 Kawakami et al. 66/157 2 Ch 6 D'awmg mgulms 7/0 H flWZ'f/fll/ 0/" /i Z!) II,

flflffil/T 5764/41 Z/ 20 f/fi/f/fll fliflt'cffiflfi SEARCH ROOM PATENFEEMW 13 I975 SHEET 18F 2 kmwmwmu S PMENFEUHUV 13 ms SHEET 2 [IF 2 ELEMENTPOSITION DETECTOR SYSTEM BACKGROUND OF THE INVENTION While thisinvention relates broadly to a sensing apparatus or system, fordetecting the relative positioning of individual elements of a series ofelements, it will be discussed in connection with a specificenvironment. Specifically, in the operation of various types of rotaryknitting machines, particularly those in which pattern changes are to beeffected by other than mechanical alteration of the equipment,malfunctioning of pattern jacks many times occurs. These errors resultprimarily from variations in cylinder eccentricity, speed of cylinderrotation, and, where the electro-magnetic or similar actuating means isused, from variations in electromagnetic phasing or in permanent magnetfield strength. Obviously, if these variations result in the productionof imperfect fabric due to improper knitting, loss of both time andmoney results. It is therefore desirable for the machine user to havesome instant or ready indication that there is malfunctioning in thepattem jack operation.

SUMMARY OF THE INVENTION As noted earlier the detector system of thisinvention is particularly applicable for use in conjunction withcircular knitting machines in which the pattern jacks can beautomatically changed through the application of an appropriatelyapplied magnetic field, although the concept is applicable with othertypes of equipment where similar sensing is of value and should,therefore, not be narrowly interpreted. The detector system utilizes asensor element, capable of projecting and receiving light which islocated on the knitting machine with one face operably adjacent thetricks of the needle cylinder so that light projected from the emitterand receptor face will strike the edges of the pattern jacks as theymove past the sensing site. At least a pair of light c o n dgcting fibrecables one of which trams Em from asTtitabl' smefo the emitter-receiverface of the element and the other of which is operably joined to a lightreceiving voltage generatonThe signal derived from the voltage generatoris appropriately shaped and amplified so that a usable signal can be fedto a comparator logic system. in the logic system the signal derivedfrom the voltage generator is compared with the signal from the jackactuator command to determine the presence of any malfunctioning. Thesystem also provides for comparison between the command output and othersignals derived from the voltage generator output to determine whatparticular type of malfunctioning has occurred.

It is a principal object of this invention to provide a new sensordevice for sensing the relative positioning of individual elements in aseries of elements as they pass a sensing site.

Another object of this invention is to provide a sensor device for usein conjunction with electro-magnetically operated jack positioningdevices on rotary knitting equipment.

It is an additional object of this invention to provide an improvedsensing device in which light is reflected from the edges of the patternjacks and the received reflected light is converted into a signal thatcan be used to determine the presence or absence of machinemalfunctioning.

Another object of this invention is to provide an improved detectorsystem which can determine whether a pattern jack has passed itsoperating stage in either a knit or a non-knit position erroneously.

Other objects and advantages of this invention will, in part, be obviousand in part explained by reference to the accompanying specification anddrawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing thegeneral relationship between the edges of the pattern jacks, the lightemitting and receiving sensor and associated reflected light receivingvoltage generating means.

FIG. 2 is an enlarged perspective showing the general construction ofthe light emitting and receiving sensor of FIG. 1.

FIG. 3 is a schematic diagram illustrating the manner in which theoutput sensed from the moving elements can be compared with a commandinput signal.

FIG. 4 is a series of graphs showing the relationship between properjack positioning and the various derived outputs on a 1X1 select jackpattern.

FIG. 5 is a schematic similar to that of FIG. 4 showing the signalsderived when a jack passes the sensing site at an erroneous elevatedlevel.

FIG. 6 is a schematic similar to that of FIG. 5 but showing the outputsderived when a jack passes the sensing site below the selected level.

'It was ealier mentioned that the detector system of this invention isuseful in determining the relative positioning of any sort of elementmoving past a detecting site. However, in outlining the invention, itwill be described with particular application toa rotary knittingmachine.

The type of knitting machine with which this invention is mostapplicable is one in which the pattern jacks can be automaticallyadjusted to either a position where it will cause the knitting needlesto knit or not to knit. This is accomplished through the use of anelectro-magnetic control system including an electromagneticallyfunctioning jack actuator which is operated by a command system,specifically a computer input. Machines of this type generally comprisea large number of knitting stations or feeds, although it would also beapplicable to relatively small diameter machines with a small number ofyard feed stations. In the co-pending application of R. G. Wolfshagen,Ser. No. 135,3l9, filed Apr. 19, I971, (docket 1676) there is describeda complete jack actuator system as used on a machine'having 48 feedstations and therefore 48 jack actuator arrays. In this sort of knittingmachine the electromagnetic jack actuators are positioned reasonablycritically. with respect to the edges of the pattern jacks as they passby a selecting site. If during the course of operationmisalignmentshould occur it opens the possibility of jack actuation notoccurring as it should in response to a command input. When this happensit is of course essential that the malfunctioning be located promptlyand the cause for the malfunctioning appropriately corrected.

To describe the invention in greater detail, reference is made to FIG. 1of the drawings where the numeral 10 illustrates diagrammatically theedges of pattern jacks as they would be in a 1X1 select position. Thatis at the given site only every other one of the needles will be causedto move to the knit position and the alternate needles will remain inthe non-knit position. Situated operably adjacent the edges of thepattern jacks is a sensor 11 which comprises a head 12 and a pair of fibreoptic cables 13 and 14 which are capable of transmitting oiconductinglight from and to the head 12. On

the side of the head 12 adjacent the edges of the pattern jacks 10 is anemitter-receiving face 15 where the signal and the output signal fromthe sensor means, that light source which is to supply light to thelowermost operably adjacent the other of the optic fibre cables 1 (14)is a receiver 21 for the light which is being emitted from the cable 14.This receiver 21 may appropriately be a photocell which will take thelight being conducted to it and convert it into a voltage pulse. Thephotocell 21 is connected to a signal processor 22 which serves tosharpen and improve the nature of the voltage pulse received fromphotocell 21. Signal processer 22 may advantageously be a saturatingamplifier which will shape the analog signal and square it to deliver acleaner signal. The signal processer 22 then delivers an output signalwhich is connected to additional apparatus. I

f The operation of that part of the senso'r described thus far is asfollows. Light from source 20is displayed to the fibre cable 13 and thislight is emitted from the face 15 of head 12, so that it willstrike anyof the jacks 10 which are in the lowered or non-knit position, as viewedin FIG. 1. When light strikes one of the pattern jacks, a certainpercentage of it is reflected back and is transmitted through the fibresthat are contained in the uppermost cable 14 to then activate thephotocell 21. The photocell 21 then delivers a voltage pulse to thesignal processer for subsequent application. When there is no jackpresent opposite the emittor-receptor face of head 12 then insufficientlight will be reflected back to activate the voltage generatingphotocell 21. In the case of knitting equipment the light reflected fromthe emittor-receptor face can be adjusted to strike the needle or jackbutts so that reflection from the needle cylinder is not a significantfactor. The system can then differentiate between the presence orabsence of any given jack (or other type of passing element) by means ofdetermining whether or not light is being reflected back to result inthe generation of a-voltage pulse.

Since malfunctioning may occur by having a jackactuator in either anerroneous knit or an erroneous nonknit position, that is, in a raised orlowered position as shown in the drawings, it is obvious that meansshould be provided to determine the specific nature of themalfunctioning that is occurring. This is accomplished by means of thecircuit illustrated in the diagram shown in FIG. 6 of the drawings. Herethe output signal derived'from signal processor 22 in FIG. 1 is fed intothe jack position sensor output and then connected to a one-shotmultivibrator 25 that will deliver a pulse of constant amplitude andlength regardless of machine speed. The other input to the comparatorsystem of FIG. 6 is the actuator command, which comes from the centralcommand system that controls the actuation or pulsing of the individualjack actuator mechanisms at each yarn feed station.

The overall system then comprises first gating means 26 for receiving asinput signals the actuator command is, the signal derived from processor22. If a signal is received from the output sensor and the actuatorcommand coincidentally, then no output signal will come from gatingmeans 26 and proper operation of the apparatus will be indicated. Secondgating means 27 re ceives the output signal from gate 26 and theactuator command signal to give a first error signal indicating that ajack has passed the sensor means 11 in an improper position.Specifically, it identifies the error as one where a jack is in thenon-knit wrongly.

Third gating means 28 receives the output signal from gate 26 and theoutput signal from the command system to indicate that a jack has passedthe sensor means 11 in the knit or uppennost position erroneously. Theoutput of the gating elements 27 and 28 are indicated in FIG. 6 todeliver a down error signal and an up-error signal, respectively. Anadditional gate 29 is provided which receives as input signals thosederived from gate elements 27 and 28 and has been labelled as an ORgate29. As indicated, this gate will give a positive indiction of allerrors that have occurred, whether up or down.

Describingthe operation of the system of FIG. 6 slightly differently,the actuator command signal is fed into NAND gate 26'with the jackposition sensor output so. that no signal occurs at pulse coincidencebut signals do occur for all other combinations. The output signal fromNAND gate 26 is then forwarded to AND gate 27 with the jack positioninput pulse to yield a down errorsignal. The output signal from NANDgate 26 is also forwarded to AND gate 27 with the actuator commandsignal and from this is derived the up error signal. By forwarding thesignals from'ANl gate 27 and 28 to OR gate 29 all errors are detected,as noted earlier.

The manner in which the pulses interact to deliver the indication ofmalfunction can best be described by referring to FIGS. 3, 4 and 5 ofthe drawings. Referring first to FIG. 3 there is shown a vertical seriesof five outputs which occur at various edges of the detecting operation.The uppermost of the six vertical elements present in FIG. 3 isrepresentative of the positions the jacks should correctly assume in a1X1 pattern select. In this case it can be seen that every other jack isin the down or non-knit position with alternating jacks being in theupper or knit position. When the jacks are in the non-knit loweredposition the light being emitted and received through sensor head 12will cause the photocell 21 to generate pulses which coincide with thepassage of a lower jack past the detecting site. Again, as earlierdescribed, the voltage pulse coming from the photocell 21 goes throughsignal processor 22 and is processed to deliver an improved signal. Thefourth vertical line from the top of the vertical series of curvesrepresents the input derived from the actuator command or input signalsystem. It can be seen that the pulses received, as generated byphotocell 21, coincide with the clocking pulses received from thecommand system. When this occurs the lower two lines indicate that thereare no detector output signals that would indicate any sort of machinemalfunction. Comparing the curves of FIG. 3 with those of FIG. 4 it willbe noted that the jack numbered 30" is in a raised position, whereas. tobe properly located it should be in a lower position. This, of course,results in the absence of a pulse from the jack position sensor outputwhile the jack actuator command as indicated with a pulse should bepresent. Operating through the system of FIG. 6 then, the inputs wouldresult in NAND gate 26 and AND gate 28 combining to produce an up errorsignal.

Conversely the curves of FIG. 5 demonstrate what the condition of thesystem is when a jack 31 is in a lower or down position erroneously.Here an extra pulse is produced by the jack position sensor while one isnot called for the command system. When this occurs, NAND gate 26 andAND gate 27 should deliver an indication of a down error.

This detector is far less sensitive to cylinder eccentricity andcylinder to detector Spacing than the conventional magnetic sensorswhich are adversely affected by cylinder velocity and jack to sensordistance and the presence of magnetic fields.

Although the present invention has been described in connection withpreferred embodiments, it is to be understood that modifications andvariations may be resorted to without departing from the spirit andscope of the invention, as those skilled in the art will readilyunderstand. Such modifications and variations are considered to bewithin the purview and scope of the invention and the appended claims.

We claim:

1. A detector system for use with a circular knitting machine on whichthe pattern jacks carried within the tricks of the needle cylinder areselected by electronically regulated jack actuators controlled by anactuator command system to be either raised to a knit position by jackraising cams or left in a lower non-knit position, as desired, saiddetector system comprising:

sensor means for positioning operably adjacent the needle cylinder forprojecting light against the edges ofjacks in the non-knit position andfor collecting a portion of the light reflected by the edges; and

means associated with said sensor means to generate a voltage outputsignal indicative of the passage of a jack in the non-knit position pastsaid sensor means.

2. A detector system as described in claim 1 wherein aid sensor meanscomprises at least two light conductng fibre cables terminating in anemitter and receptor face fofiio's idoning adjacent the edges of saidjacks, one of said cables being operably connected to a source of lightand the other of said cables being operably joined to a light responsivevoltage generator.

it t a e

1. A detector system for use with a circular knitting machine on which the pattern jacks carried within the tricks of the needle cylinder are selected by electronically regulated jack actuators controlled by an actuator command system to be either raised to a knit position by jack raising cams or left in a lower non-knit position, as desired, said detector system comprising: sensor means for positioning operably adjacent the needle cylinder for projecting light against the edges of jacks in the non-knit position and for collecting a portion of the light reflected by the edges; and means associated with said sensor means to generate a voltage output signal indicative of the passage of a jack in the nonknit position past said sensor means.
 2. A detector system as described in claim 1 wherein said sensor means comprises at least two light conducting fibre cables terminating in an emitter and receptor face for positioning adjacent the edges of said jacks, one of said cables being operably connected to a source of light and the other of said cables being operably joined to a light responsive voltage generator. 